Understanding and control of kidney bean wilt disease

Kidney bean is a temperature-loving plant. The suitable temperature for growth is 15: 25 ℃, and the suitable temperature for flowering and pod setting is 20: 25 ℃. Low temperature below 10 ℃ or high temperature above 30 ℃ will affect growth and normal pollination and pod setting. It belongs to short sunshine plant, but most varieties do not have strict requirements for sunshine length, and the cultivation season is mainly restricted by temperature. Northwest and northeast China are cultivated in spring and summer; spring and autumn sowing in North China, Yangtze River Basin and South China.

Kidney beans are rich in nutrition, and fresh beans are also rich in vitamin C. In terms of nutrients, the content of protein is higher than that of chicken, the content of calcium is more than 7 times that of chicken, the content of iron is 4 times, and B vitamins are also higher than chicken.

Edible value of kidney bean

The tender pod contains about 6% protein, 10% fiber and 1% sugar. Dried beans contain about 22.5% protein and 59.6% starch. Fresh and tender pods can be eaten as vegetables, dehydrated or canned. Kidney bean is also a rare food with high potassium, high magnesium and low sodium, which has a great opportunity to show its ability in nutritional therapy. Kidney beans are especially suitable for patients with heart disease, arteriosclerosis, hyperlipidemia, hypokalemia and salt taboo.

Medicinal value of kidney bean

According to modern medical analysis, kidney bean also contains unique ingredients such as saponins, urease and a variety of globulins, which can improve the immunity of human body, enhance disease resistance, activate lymphoid T cells, and promote the synthesis of deoxyribonucleic acid. It has an inhibitory effect on the development of tumor cells, so it has been paid attention to by the medical community. Its content of urease is very effective in patients with hepatic coma.

Understanding and control of kidney bean wilt disease

What is wilt disease?

A general term for plant diseases such as Fusarium wilt, Verticillium wilt and bacterial wilt caused by Fusarium, Verticillium and Pseudomonas respectively. The Fusarium oxysporum fungi causing Fusarium wilt have high parasitic specificity, for example, Fusarium oxysporum has more than 70 specific types infecting certain hosts respectively. Although the pathogenicity of Fusarium oxysporum fungi of the same species is very wide, their pathogenicity is obviously different. The pathogenicity of Pseudomonas solanacearum was also significantly different on different hosts.

The pathogen of kidney bean wilt is Brevibacterium pumilus, Gram-positive, can move, does not produce spores, 0.3-0.5 × 0.6-3.0 μ m, 1 color 3 lateral or polar whips, until slightly curved or wedge-shaped, single or V, Y-shaped or palisade arrangement.

Harmful symptoms of kidney bean wilt: kidney bean wilt infects seedlings through diseased seeds or overwintering residues, usually causing death. If the seedlings survive, there are no leaves to grow. The most typical symptom of kidney bean is the gradual wilting of seedling leaves, accompanied by discoloration and dwarfing of plants. The young branches wither and die. Discolored leaves usually have dark green, brown or reddish brown disease spots, the discoloration area softens at first, then dries up, and the leaves are inoculated with water stains to produce white bubbles. Sometimes in the absence of the above symptoms, the leaves showed golden necrotic spots or only partial wilting, similar to kidney bean common blight (Xanthomones campestris pv. Phaseoli) is similar, but after the kidney pod is infected, there are discoloration spots along the pod seam, usually yellowish green, some wilting, and sometimes sunken surface. On the mature pods, the disease spots are green-brown and the rest are yellow. Susceptible seeds have yellow disease spots of different sizes and shapes, which can be easily distinguished from healthy seeds.

When you open the pod, you can see that there are yellow bacterial pus with water stains on the stems and leaves. There are generally rust spots on the kidney bean stem, the pathogen survives in the vascular bundle and browns it, and the stem inoculation produces leaf vein yellowing and necrosis. The orange and purple mutants infected the seeds with orange and purple discoloration spots on the seed coat. Both seedlings and adults of soybean are susceptible to the disease. The leaves first appeared small chlorotic spots, then expanded, and began to fade to the midrib along the edge of the leaf. The susceptible tissue dries, browns and dies. In the case of wind, the browning part falls off and the leaves appear rough. When planting infected seeds, the seedlings were dwarfed, the edge of the leaves were necrotic or there were necrotic spots on the leaves, and the formation of pods was abnormal, but no symptoms were observed on pods and stems.

Control methods of kidney bean wilt pathogen:

The main ways of prevention and control include strict quarantine protection of disease-free areas, selection of disease-resistant varieties in disease areas, rotation, disinfection of seeds with bacteria, and replanting or soil disinfection in seriously diseased fields.

1) the seeds were soaked in 56 ℃ warm water for 5 minutes before disinfection and sowing.

2) crop rotation has been implemented for more than 3 years and paddy fields for more than 2 years.

3) choose fields with soil water content higher than 70% to plant.